In recent signboard advertisement, there are increasing number of photo-like objects such as an appearance of a commercial article and a face of a person besides logotypes and patterns of a vivid and sophisticated design. Further, many large size advertisement boards are seen in order to give viewers a stronger impact. So far, for making an advertisement board, usually a colored sheet is cut into shapes of characters and paste up them on the board in the case of logotypes, and various printers are used in the case of photo-like objects. Therefore, there was a problem such that it took a lot of time and labor for manufacturing of the board, and a large-scale printer was required. So, in order to easily manufacture an advertisement board having a vivid image thereon, a trial for using an ink jet method which can print a design created in a personal computer directly on a substrate has been attempted.
An ink jet method is characterized in that a width of a material usable as a printing substrate is wide and printing can be made easily even on sheets made of paper, polymer, metal and other hard and soft materials. In particular, in the case of an advertisement board installed outside, characteristics such as a light weight, excellent strength and durability, weather resistance and low cost are demanded. Therefore, being capable of easily printing on a polymer sheet having such characteristics is a great merit. In addition thereto, recently an ink jet printer of an ultra wide format having a printing width of 2,000 mm or more is available, thereby enabling a large-size printed matter to be printed at a stroke though the large-size advertisement board has been made by pasting. Thus, advertisement boards will be able to be manufactured more easily.
Generally a polymer sheet called Tarpaulin is used as a polymer sheet used on advertisement boards. Tarpaulin is a complex sheet manufactured by using polyester or polyamide as a core material and applying a vinyl polymer such as polyvinyl chloride or an ethylene-vinyl acetate copolymer to top and bottom surfaces of the core material. A non-aqueous ink composition for ink jet printing prepared using an organic solvent (recently environmentally friendly organic solvent) as a base material is used as an ink composition for ink jet printing printed on such a complex sheet. It is necessary to use, as a non-aqueous ink composition for ink jet printing, materials having good wettability, drying characteristics and fixing property relative to polyvinyl chloride or an ethylene-vinyl acetate copolymer which is a material used on top and bottom surfaces of the core material.
By the way, among non-aqueous ink jet inks, different hues are demanded for a non-aqueous magenta ink composition for ink jet printing in various countries. Especially in China and Korea, such non-aqueous magenta ink composition for ink jet printing has strong yellowness (high b* value). In order to exhibit a color having such a strong yellowness, an ink jet ink using a pigment comprising C.I. Pigment Red 146 has been proposed in Patent Document 1.